As you already mentioned Luis' estimate of a "manpower" is definitly too high. 150 watts is a good estimate, but this is already hard cycling. (But we probably could assume the poor man is well trained if he's charging other people's batteries for a living.) What is still missing in this considerations is, that some of the power will be diverted before it reaches the dynamo (friction). The convertion of mechanical energy to electrical energy will also not be lossless, and so won't be the charging of the battery (do lead batteries also get warm while charging? I don't know).

On the other hand is 100 Ah already a high value for a car battery (At least from a quick google research.) The typical value seems to be more like 40 to 60 Ah. The rest of your estimate seems reasonable to me, so this would result in maybe 5-7 h cycling. (Which is not too much anymore, if it can be spread over a month.)

But you'd first need a dynamo which really is capable of delivering that kind of energy. A regular bicycle dynamo won't, they are designed to work at a power level of 3 W.

I guess this is the main problem in the bicycle idea. And this is also the reason why solar power is not employed.
On the one hand it's missing knowledge. They don't know about the possiblities and even if they knew, they would still need customized solutions, which either requires good electronic knowledge and the right tools to make them, or it requires the money to buy them (usually from the west or the far east).
On the other hand, from what I heard, the concept of saving money in order to have a sum for investing into something some time in the future, to not have to spend some money even in a more distant future, is not very widely spread. This probably requires good education, which is something unfortunately missing in many african countries (I don't know about the special case of Uganda.)

On the other hand, from what I heard, the concept of saving money in order to have a sum for investing into something some time in the future, to not have to spend some money even in a more distant future, is not very widely spread.

And on yet another hand, if you're poor you can't afford to spend much on anything. I've been in places where neighborhood stores will sell an individual cigarette. Or an individual Pamper (nappy/diaper). And at the Colombia/Brazil border you could buy gasoline by the jar - small glass jars laid out on tables in the blazing sun!

On the other hand, from what I heard, the concept of saving money in order to have a sum for investing into something some time in the future, to not have to spend some money even in a more distant future, is not very widely spread. This probably requires good education, which is something unfortunately missing in many african countries (I don't know about the special case of Uganda.)

It also requires that you actually have enough money to be able to set some aside. Most of these people are barely scraping by as it is, and any money they can save will doubtless have higher priorities.

On a completely unrelated note, I find the advertisment for battery charging and "good acid" rather amusing... But I guess that's showing my misspent youth.

As you already mentioned Luis' estimate of a "manpower" is definitly too high. 150 watts is a good estimate, but this is already hard cycling.

Nope. Wrong. Lance Armstrong would pull a peak of 600 watts. I pull 400 watts and at 500+ watts I taste blood and develop a nasty hack for 2 months.

200 watts is a nice pace.

Your comment about those poorly educated
Africans being too benighted to ever think of
saving for future investment is not only
condescending, but boorish.

Do you have solar panels, stax? If not, I
have to assume that it's you are a victim of
poor education and those happy-go-lucky
cultural values that rendered you incapable
of planning for the future. I'll bet your
friends and neighbors are also betraying these
same symptoms of weak characters and weak minds.